From Gluten-Free Trading Company

What is gluten?

Gluten is a protein found in wheat, barley, rye, and some related grains. Gluten makes baked goods stretchy and flaky (croissants and puff pastry are made with high-gluten flour).

Gluten is not the same thing as starch. If you took a pound of wheat flour and mixed it into a thick dough, in an hour or two you could gradually wash away the starch under a gentle trickle of running water. You would be left with about 2 ounces of a rubbery substance: that's the gluten!

Always make sure the grains and starches you buy come from clean, uncontaminated sources!

What Are Some Easily Overlooked Sources of Gluten?

Ordinary baked goods such as bread, rolls, cookies, crackers, and pizza crusts are fairly obvious sources of gluten. Ingredients derived from wheat and barley are also used in many other foods, including various products that do not have starchy textures. Here are some foods and ingredients that might contain gluten:

Barley Malt, also known as Malt Flavoring (often found in breakfast cereals such as Rice Krispies).